src/vnet/lisp-gpe/decap.c - fdio/vpp - Gitiles

 /*
  * Copyright (c) 2016 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 /**
  * @file
  * @brief L2 LISP-GPE decap code.
  *
  */
 #include <vlib/vlib.h>
 #include <vnet/pg/pg.h>
 #include <vnet/lisp-gpe/lisp_gpe.h>

 typedef struct
 {
   u32 next_index;
   u32 tunnel_index;
   u32 error;
   lisp_gpe_header_t h;
 } lisp_gpe_rx_trace_t;

 static u8 *
 format_lisp_gpe_rx_trace (u8 * s, va_list * args)
 {
   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
   lisp_gpe_rx_trace_t *t = va_arg (*args, lisp_gpe_rx_trace_t *);

   if (t->tunnel_index != ~0)
     {
       s = format (s, "LISP-GPE: tunnel %d next %d error %d", t->tunnel_index,
 		  t->next_index, t->error);
     }
   else
     {
       s = format (s, "LISP-GPE: no tunnel next %d error %d\n", t->next_index,
 		  t->error);
     }
   s = format (s, "\n  %U", format_lisp_gpe_header_with_length, &t->h,
 	      (u32) sizeof (t->h) /* max size */ );
   return s;
 }

 static u32 next_proto_to_next_index[LISP_GPE_NEXT_PROTOS] = {
   LISP_GPE_INPUT_NEXT_DROP,
   LISP_GPE_INPUT_NEXT_IP4_INPUT,
   LISP_GPE_INPUT_NEXT_IP6_INPUT,
   LISP_GPE_INPUT_NEXT_L2_INPUT,
   LISP_GPE_INPUT_NEXT_DROP
 };

 always_inline u32
 next_protocol_to_next_index (lisp_gpe_header_t * lgh, u8 * next_header)
 {
   lisp_gpe_main_t *lgm = vnet_lisp_gpe_get_main ();

   /* lisp-gpe router */
   if (PREDICT_TRUE ((lgh->flags & LISP_GPE_FLAGS_P)
 		    || GPE_ENCAP_VXLAN == lgm->encap_mode))
     {
       if (PREDICT_FALSE (lgh->next_protocol >= LISP_GPE_NEXT_PROTOS))
 	return LISP_GPE_INPUT_NEXT_DROP;

       return next_proto_to_next_index[lgh->next_protocol];
     }
   /* legacy lisp router */
   else if ((lgh->flags & LISP_GPE_FLAGS_P) == 0)
     {
       ip4_header_t *iph = (ip4_header_t *) next_header;
       if ((iph->ip_version_and_header_length & 0xF0) == 0x40)
 	return LISP_GPE_INPUT_NEXT_IP4_INPUT;
       else if ((iph->ip_version_and_header_length & 0xF0) == 0x60)
 	return LISP_GPE_INPUT_NEXT_IP6_INPUT;
       else
 	return LISP_GPE_INPUT_NEXT_DROP;
     }
   else
     return LISP_GPE_INPUT_NEXT_DROP;
 }

 always_inline tunnel_lookup_t *
 next_index_to_iface (lisp_gpe_main_t * lgm, u32 next_index)
 {
   if (LISP_GPE_INPUT_NEXT_IP4_INPUT == next_index
       || LISP_GPE_INPUT_NEXT_IP6_INPUT == next_index)
     return &lgm->l3_ifaces;
   else if (LISP_GPE_INPUT_NEXT_L2_INPUT == next_index)
     return &lgm->l2_ifaces;
   else if (LISP_GPE_INPUT_NEXT_NSH_INPUT == next_index)
     return &lgm->nsh_ifaces;
   clib_warning ("next_index not associated to an interface!");
   return 0;
 }

 static_always_inline void
 incr_decap_stats (vnet_main_t * vnm, u32 cpu_index, u32 length,
 		  u32 sw_if_index, u32 * last_sw_if_index, u32 * n_packets,
 		  u32 * n_bytes)
 {
   vnet_interface_main_t *im;

   if (PREDICT_TRUE (sw_if_index == *last_sw_if_index))
     {
       *n_packets += 1;
       *n_bytes += length;
     }
   else
     {
       if (PREDICT_TRUE (*last_sw_if_index != ~0))
 	{
 	  im = &vnm->interface_main;

 	  vlib_increment_combined_counter (im->combined_sw_if_counters +
 					   VNET_INTERFACE_COUNTER_RX,
 					   cpu_index, *last_sw_if_index,
 					   *n_packets, *n_bytes);
 	}
       *last_sw_if_index = sw_if_index;
       *n_packets = 1;
       *n_bytes = length;
     }
 }

 /**
  * @brief LISP-GPE decap dispatcher.
  * @node lisp_gpe_input_inline
  *
  * LISP-GPE decap dispatcher.
  *
  * Decaps IP-UDP-LISP-GPE header and based on the next protocol and in the
  * GPE header and the vni decides the next node to forward the packet to.
  *
  * @param[in]   vm      vlib_main_t corresponding to current thread.
  * @param[in]   node    vlib_node_runtime_t data for this node.
  * @param[in]   frame   vlib_frame_t whose contents should be dispatched.
  *
  * @return number of vectors in frame.
  */
 static uword
 lisp_gpe_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 		       vlib_frame_t * from_frame, u8 is_v4)
 {
   u32 n_left_from, next_index, *from, *to_next, cpu_index;
   u32 n_bytes = 0, n_packets = 0, last_sw_if_index = ~0, drops = 0;
   lisp_gpe_main_t *lgm = vnet_lisp_gpe_get_main ();

   cpu_index = os_get_cpu_number ();
   from = vlib_frame_vector_args (from_frame);
   n_left_from = from_frame->n_vectors;

   next_index = node->cached_next_index;

   while (n_left_from > 0)
     {
       u32 n_left_to_next;

       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

       while (n_left_from >= 4 && n_left_to_next >= 2)
 	{
 	  u32 bi0, bi1;
 	  vlib_buffer_t *b0, *b1;
 	  ip4_udp_lisp_gpe_header_t *iul4_0, *iul4_1;
 	  ip6_udp_lisp_gpe_header_t *iul6_0, *iul6_1;
 	  lisp_gpe_header_t *lh0, *lh1;
 	  u32 next0, next1, error0, error1;
 	  uword *si0, *si1;
 	  tunnel_lookup_t *tl0, *tl1;

 	  /* Prefetch next iteration. */
 	  {
 	    vlib_buffer_t *p2, *p3;

 	    p2 = vlib_get_buffer (vm, from[2]);
 	    p3 = vlib_get_buffer (vm, from[3]);

 	    vlib_prefetch_buffer_header (p2, LOAD);
 	    vlib_prefetch_buffer_header (p3, LOAD);

 	    CLIB_PREFETCH (p2->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
 	    CLIB_PREFETCH (p3->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
 	  }

 	  bi0 = from[0];
 	  bi1 = from[1];
 	  to_next[0] = bi0;
 	  to_next[1] = bi1;
 	  from += 2;
 	  to_next += 2;
 	  n_left_to_next -= 2;
 	  n_left_from -= 2;

 	  b0 = vlib_get_buffer (vm, bi0);
 	  b1 = vlib_get_buffer (vm, bi1);

 	  /* udp leaves current_data pointing at the lisp header */
 	  if (is_v4)
 	    {
 	      vlib_buffer_advance (b0,
 				   -(word) (sizeof (udp_header_t) +
 					    sizeof (ip4_header_t)));
 	      vlib_buffer_advance (b1,
 				   -(word) (sizeof (udp_header_t) +
 					    sizeof (ip4_header_t)));

 	      iul4_0 = vlib_buffer_get_current (b0);
 	      iul4_1 = vlib_buffer_get_current (b1);

 	      /* pop (ip, udp, lisp-gpe) */
 	      vlib_buffer_advance (b0, sizeof (*iul4_0));
 	      vlib_buffer_advance (b1, sizeof (*iul4_1));

 	      lh0 = &iul4_0->lisp;
 	      lh1 = &iul4_1->lisp;
 	    }
 	  else
 	    {
 	      vlib_buffer_advance (b0,
 				   -(word) (sizeof (udp_header_t) +
 					    sizeof (ip6_header_t)));
 	      vlib_buffer_advance (b1,
 				   -(word) (sizeof (udp_header_t) +
 					    sizeof (ip6_header_t)));

 	      iul6_0 = vlib_buffer_get_current (b0);
 	      iul6_1 = vlib_buffer_get_current (b1);

 	      /* pop (ip, udp, lisp-gpe) */
 	      vlib_buffer_advance (b0, sizeof (*iul6_0));
 	      vlib_buffer_advance (b1, sizeof (*iul6_1));

 	      lh0 = &iul6_0->lisp;
 	      lh1 = &iul6_1->lisp;
 	    }

 	  /* determine next_index from lisp-gpe header */
 	  next0 = next_protocol_to_next_index (lh0,
 					       vlib_buffer_get_current (b0));
 	  next1 = next_protocol_to_next_index (lh1,
 					       vlib_buffer_get_current (b1));

 	  /* determine if tunnel is l2 or l3 */
 	  tl0 = next_index_to_iface (lgm, next0);
 	  tl1 = next_index_to_iface (lgm, next1);

 	  /* map iid/vni to lisp-gpe sw_if_index which is used by ipx_input to
 	   * decide the rx vrf and the input features to be applied */
 	  si0 = hash_get (tl0->sw_if_index_by_vni,
 			  clib_net_to_host_u32 (lh0->iid << 8));
 	  si1 = hash_get (tl1->sw_if_index_by_vni,
 			  clib_net_to_host_u32 (lh1->iid << 8));


 	  /* Required to make the l2 tag push / pop code work on l2 subifs */
 	  vnet_update_l2_len (b0);
 	  vnet_update_l2_len (b1);

 	  if (si0)
 	    {
 	      incr_decap_stats (lgm->vnet_main, cpu_index,
 				vlib_buffer_length_in_chain (vm, b0), si0[0],
 				&last_sw_if_index, &n_packets, &n_bytes);
 	      vnet_buffer (b0)->sw_if_index[VLIB_RX] = si0[0];
 	      error0 = 0;
 	    }
 	  else
 	    {
 	      next0 = LISP_GPE_INPUT_NEXT_DROP;
 	      error0 = LISP_GPE_ERROR_NO_TUNNEL;
 	      drops++;
 	    }

 	  if (si1)
 	    {
 	      incr_decap_stats (lgm->vnet_main, cpu_index,
 				vlib_buffer_length_in_chain (vm, b1), si1[0],
 				&last_sw_if_index, &n_packets, &n_bytes);
 	      vnet_buffer (b1)->sw_if_index[VLIB_RX] = si1[0];
 	      error1 = 0;
 	    }
 	  else
 	    {
 	      next1 = LISP_GPE_INPUT_NEXT_DROP;
 	      error1 = LISP_GPE_ERROR_NO_TUNNEL;
 	      drops++;
 	    }

 	  b0->error = error0 ? node->errors[error0] : 0;
 	  b1->error = error1 ? node->errors[error1] : 0;

 	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      lisp_gpe_rx_trace_t *tr = vlib_add_trace (vm, node, b0,
 							sizeof (*tr));
 	      tr->next_index = next0;
 	      tr->error = error0;
 	      tr->h = lh0[0];
 	    }

 	  if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      lisp_gpe_rx_trace_t *tr = vlib_add_trace (vm, node, b1,
 							sizeof (*tr));
 	      tr->next_index = next1;
 	      tr->error = error1;
 	      tr->h = lh1[0];
 	    }

 	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next,
 					   n_left_to_next, bi0, bi1, next0,
 					   next1);
 	}

       while (n_left_from > 0 && n_left_to_next > 0)
 	{
 	  u32 bi0;
 	  vlib_buffer_t *b0;
 	  u32 next0;
 	  ip4_udp_lisp_gpe_header_t *iul4_0;
 	  ip6_udp_lisp_gpe_header_t *iul6_0;
 	  lisp_gpe_header_t *lh0;
 	  u32 error0;
 	  uword *si0;
 	  tunnel_lookup_t *tl0;

 	  bi0 = from[0];
 	  to_next[0] = bi0;
 	  from += 1;
 	  to_next += 1;
 	  n_left_from -= 1;
 	  n_left_to_next -= 1;

 	  b0 = vlib_get_buffer (vm, bi0);

 	  /* udp leaves current_data pointing at the lisp header
 	   * TODO: there's no difference in processing between v4 and v6
 	   * encapsulated packets so the code should be simplified if ip header
 	   * info is not going to be used for dp smrs/dpsec */
 	  if (is_v4)
 	    {
 	      vlib_buffer_advance (b0,
 				   -(word) (sizeof (udp_header_t) +
 					    sizeof (ip4_header_t)));

 	      iul4_0 = vlib_buffer_get_current (b0);

 	      /* pop (ip, udp, lisp-gpe) */
 	      vlib_buffer_advance (b0, sizeof (*iul4_0));

 	      lh0 = &iul4_0->lisp;
 	    }
 	  else
 	    {
 	      vlib_buffer_advance (b0,
 				   -(word) (sizeof (udp_header_t) +
 					    sizeof (ip6_header_t)));

 	      iul6_0 = vlib_buffer_get_current (b0);

 	      /* pop (ip, udp, lisp-gpe) */
 	      vlib_buffer_advance (b0, sizeof (*iul6_0));

 	      lh0 = &iul6_0->lisp;
 	    }

 	  /* TODO if security is to be implemented, something similar to RPF,
 	   * probably we'd like to check that the peer is allowed to send us
 	   * packets. For this, we should use the tunnel table OR check that
 	   * we have a mapping for the source eid and that the outer source of
 	   * the packet is one of its locators */

 	  /* determine next_index from lisp-gpe header */
 	  next0 = next_protocol_to_next_index (lh0,
 					       vlib_buffer_get_current (b0));

 	  /* determine if tunnel is l2 or l3 */
 	  tl0 = next_index_to_iface (lgm, next0);

 	  /* map iid/vni to lisp-gpe sw_if_index which is used by ipx_input to
 	   * decide the rx vrf and the input features to be applied.
 	   * NOTE: vni uses only the first 24 bits */
 	  si0 = hash_get (tl0->sw_if_index_by_vni,
 			  clib_net_to_host_u32 (lh0->iid << 8));

 	  /* Required to make the l2 tag push / pop code work on l2 subifs */
 	  vnet_update_l2_len (b0);

 	  if (si0)
 	    {
 	      incr_decap_stats (lgm->vnet_main, cpu_index,
 				vlib_buffer_length_in_chain (vm, b0), si0[0],
 				&last_sw_if_index, &n_packets, &n_bytes);
 	      vnet_buffer (b0)->sw_if_index[VLIB_RX] = si0[0];
 	      error0 = 0;
 	    }
 	  else
 	    {
 	      next0 = LISP_GPE_INPUT_NEXT_DROP;
 	      error0 = LISP_GPE_ERROR_NO_TUNNEL;
 	      drops++;
 	    }

 	  /* TODO error handling if security is implemented */
 	  b0->error = error0 ? node->errors[error0] : 0;

 	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      lisp_gpe_rx_trace_t *tr = vlib_add_trace (vm, node, b0,
 							sizeof (*tr));
 	      tr->next_index = next0;
 	      tr->error = error0;
 	      tr->h = lh0[0];
 	    }

 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 					   n_left_to_next, bi0, next0);
 	}

       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
     }

   /* flush iface stats */
   incr_decap_stats (lgm->vnet_main, cpu_index, 0, ~0, &last_sw_if_index,
 		    &n_packets, &n_bytes);
   vlib_node_increment_counter (vm, lisp_gpe_ip4_input_node.index,
 			       LISP_GPE_ERROR_NO_TUNNEL, drops);
   return from_frame->n_vectors;
 }

 static uword
 lisp_gpe_ip4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
 		    vlib_frame_t * from_frame)
 {
   return lisp_gpe_input_inline (vm, node, from_frame, 1);
 }

 static uword
 lisp_gpe_ip6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
 		    vlib_frame_t * from_frame)
 {
   return lisp_gpe_input_inline (vm, node, from_frame, 0);
 }

 static char *lisp_gpe_ip4_input_error_strings[] = {
 #define lisp_gpe_error(n,s) s,
 #include <vnet/lisp-gpe/lisp_gpe_error.def>
 #undef lisp_gpe_error
 };

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (lisp_gpe_ip4_input_node) = {
   .function = lisp_gpe_ip4_input,
   .name = "lisp-gpe-ip4-input",
   /* Takes a vector of packets. */
   .vector_size = sizeof (u32),
   .n_next_nodes = LISP_GPE_INPUT_N_NEXT,
   .next_nodes = {
 #define _(s,n) [LISP_GPE_INPUT_NEXT_##s] = n,
     foreach_lisp_gpe_ip_input_next
 #undef _
   },

   .n_errors = ARRAY_LEN (lisp_gpe_ip4_input_error_strings),
   .error_strings = lisp_gpe_ip4_input_error_strings,

   .format_buffer = format_lisp_gpe_header_with_length,
   .format_trace = format_lisp_gpe_rx_trace,
   // $$$$ .unformat_buffer = unformat_lisp_gpe_header,
 };
 /* *INDENT-ON* */

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (lisp_gpe_ip6_input_node) = {
   .function = lisp_gpe_ip6_input,
   .name = "lisp-gpe-ip6-input",
   /* Takes a vector of packets. */
   .vector_size = sizeof (u32),
   .n_next_nodes = LISP_GPE_INPUT_N_NEXT,
   .next_nodes = {
 #define _(s,n) [LISP_GPE_INPUT_NEXT_##s] = n,
     foreach_lisp_gpe_ip_input_next
 #undef _
   },

   .n_errors = ARRAY_LEN (lisp_gpe_ip4_input_error_strings),
   .error_strings = lisp_gpe_ip4_input_error_strings,

   .format_buffer = format_lisp_gpe_header_with_length,
   .format_trace = format_lisp_gpe_rx_trace,
   // $$$$ .unformat_buffer = unformat_lisp_gpe_header,
 };
 /* *INDENT-ON* */

 /**
  * Adds arc from lisp-gpe-input to nsh-input if nsh-input is available
  */
 static void
 gpe_add_arc_from_input_to_nsh ()
 {
   lisp_gpe_main_t *lgm = vnet_lisp_gpe_get_main ();
   vlib_main_t *vm = lgm->vlib_main;
   vlib_node_t *nsh_input;

   /* Arc already exists */
   if (next_proto_to_next_index[LISP_GPE_NEXT_PROTO_NSH]
       != LISP_GPE_INPUT_NEXT_DROP)
     return;

   /* Check if nsh-input is available */
   if ((nsh_input = vlib_get_node_by_name (vm, (u8 *) "nsh-input")))
     {
       u32 slot4, slot6;
       slot4 = vlib_node_add_next_with_slot (vm, lisp_gpe_ip4_input_node.index,
 					    nsh_input->index,
 					    LISP_GPE_NEXT_PROTO_NSH);
       slot6 = vlib_node_add_next_with_slot (vm, lisp_gpe_ip6_input_node.index,
 					    nsh_input->index,
 					    LISP_GPE_NEXT_PROTO_NSH);
       ASSERT (slot4 == slot6 && slot4 == LISP_GPE_INPUT_NEXT_NSH_INPUT);

       next_proto_to_next_index[LISP_GPE_NEXT_PROTO_NSH] = slot4;
     }
 }

 /** GPE decap init function. */
 clib_error_t *
 gpe_decap_init (vlib_main_t * vm)
 {
   clib_error_t *error = 0;

   if ((error = vlib_call_init_function (vm, lisp_gpe_init)))
     return error;

   gpe_add_arc_from_input_to_nsh ();
   return 0;
 }

 VLIB_INIT_FUNCTION (gpe_decap_init);

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* Copyright (c) 2016 Cisco and/or its affiliates.
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	/**
	* @file
	* @brief L2 LISP-GPE decap code.
	*
	*/
	#include <vlib/vlib.h>
	#include <vnet/pg/pg.h>
	#include <vnet/lisp-gpe/lisp_gpe.h>

	typedef struct
	{
	u32 next_index;
	u32 tunnel_index;
	u32 error;
	lisp_gpe_header_t h;
	} lisp_gpe_rx_trace_t;

	static u8 *
	format_lisp_gpe_rx_trace (u8 * s, va_list * args)
	{
	CLIB_UNUSED (vlib_main_t * vm) = va_arg (args, vlib_main_t );
	CLIB_UNUSED (vlib_node_t * node) = va_arg (args, vlib_node_t );
	lisp_gpe_rx_trace_t t = va_arg (args, lisp_gpe_rx_trace_t *);

	if (t->tunnel_index != ~0)
	{
	s = format (s, "LISP-GPE: tunnel %d next %d error %d", t->tunnel_index,
	t->next_index, t->error);
	}
	else
	{
	s = format (s, "LISP-GPE: no tunnel next %d error %d\n", t->next_index,
	t->error);
	}
	s = format (s, "\n %U", format_lisp_gpe_header_with_length, &t->h,
	(u32) sizeof (t->h) /* max size */ );
	return s;
	}

	static u32 next_proto_to_next_index[LISP_GPE_NEXT_PROTOS] = {
	LISP_GPE_INPUT_NEXT_DROP,
	LISP_GPE_INPUT_NEXT_IP4_INPUT,
	LISP_GPE_INPUT_NEXT_IP6_INPUT,
	LISP_GPE_INPUT_NEXT_L2_INPUT,
	LISP_GPE_INPUT_NEXT_DROP
	};

	always_inline u32
	next_protocol_to_next_index (lisp_gpe_header_t * lgh, u8 * next_header)
	{
	lisp_gpe_main_t *lgm = vnet_lisp_gpe_get_main ();

	/* lisp-gpe router */
	if (PREDICT_TRUE ((lgh->flags & LISP_GPE_FLAGS_P)
	\|\| GPE_ENCAP_VXLAN == lgm->encap_mode))
	{
	if (PREDICT_FALSE (lgh->next_protocol >= LISP_GPE_NEXT_PROTOS))
	return LISP_GPE_INPUT_NEXT_DROP;

	return next_proto_to_next_index[lgh->next_protocol];
	}
	/* legacy lisp router */
	else if ((lgh->flags & LISP_GPE_FLAGS_P) == 0)
	{
	ip4_header_t iph = (ip4_header_t ) next_header;
	if ((iph->ip_version_and_header_length & 0xF0) == 0x40)
	return LISP_GPE_INPUT_NEXT_IP4_INPUT;
	else if ((iph->ip_version_and_header_length & 0xF0) == 0x60)
	return LISP_GPE_INPUT_NEXT_IP6_INPUT;
	else
	return LISP_GPE_INPUT_NEXT_DROP;
	}
	else
	return LISP_GPE_INPUT_NEXT_DROP;
	}

	always_inline tunnel_lookup_t *
	next_index_to_iface (lisp_gpe_main_t * lgm, u32 next_index)
	{
	if (LISP_GPE_INPUT_NEXT_IP4_INPUT == next_index
	\|\| LISP_GPE_INPUT_NEXT_IP6_INPUT == next_index)
	return &lgm->l3_ifaces;
	else if (LISP_GPE_INPUT_NEXT_L2_INPUT == next_index)
	return &lgm->l2_ifaces;
	else if (LISP_GPE_INPUT_NEXT_NSH_INPUT == next_index)
	return &lgm->nsh_ifaces;
	clib_warning ("next_index not associated to an interface!");
	return 0;
	}

	static_always_inline void
	incr_decap_stats (vnet_main_t * vnm, u32 cpu_index, u32 length,
	u32 sw_if_index, u32 * last_sw_if_index, u32 * n_packets,
	u32 * n_bytes)
	{
	vnet_interface_main_t *im;

	if (PREDICT_TRUE (sw_if_index == *last_sw_if_index))
	{
	*n_packets += 1;
	*n_bytes += length;
	}
	else
	{
	if (PREDICT_TRUE (*last_sw_if_index != ~0))
	{
	im = &vnm->interface_main;

	vlib_increment_combined_counter (im->combined_sw_if_counters +
	VNET_INTERFACE_COUNTER_RX,
	cpu_index, *last_sw_if_index,
	n_packets, n_bytes);
	}
	*last_sw_if_index = sw_if_index;
	*n_packets = 1;
	*n_bytes = length;
	}
	}

	/**
	* @brief LISP-GPE decap dispatcher.
	* @node lisp_gpe_input_inline
	*
	* LISP-GPE decap dispatcher.
	*
	* Decaps IP-UDP-LISP-GPE header and based on the next protocol and in the
	* GPE header and the vni decides the next node to forward the packet to.
	*
	* @param[in] vm vlib_main_t corresponding to current thread.
	* @param[in] node vlib_node_runtime_t data for this node.
	* @param[in] frame vlib_frame_t whose contents should be dispatched.
	*
	* @return number of vectors in frame.
	*/
	static uword
	lisp_gpe_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
	vlib_frame_t * from_frame, u8 is_v4)
	{
	u32 n_left_from, next_index, from, to_next, cpu_index;
	u32 n_bytes = 0, n_packets = 0, last_sw_if_index = ~0, drops = 0;
	lisp_gpe_main_t *lgm = vnet_lisp_gpe_get_main ();

	cpu_index = os_get_cpu_number ();
	from = vlib_frame_vector_args (from_frame);
	n_left_from = from_frame->n_vectors;

	next_index = node->cached_next_index;

	while (n_left_from > 0)
	{
	u32 n_left_to_next;

	vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

	while (n_left_from >= 4 && n_left_to_next >= 2)
	{
	u32 bi0, bi1;
	vlib_buffer_t b0, b1;
	ip4_udp_lisp_gpe_header_t iul4_0, iul4_1;
	ip6_udp_lisp_gpe_header_t iul6_0, iul6_1;
	lisp_gpe_header_t lh0, lh1;
	u32 next0, next1, error0, error1;
	uword si0, si1;
	tunnel_lookup_t tl0, tl1;

	/* Prefetch next iteration. */
	{
	vlib_buffer_t p2, p3;

	p2 = vlib_get_buffer (vm, from[2]);
	p3 = vlib_get_buffer (vm, from[3]);

	vlib_prefetch_buffer_header (p2, LOAD);
	vlib_prefetch_buffer_header (p3, LOAD);

	CLIB_PREFETCH (p2->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
	CLIB_PREFETCH (p3->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
	}

	bi0 = from[0];
	bi1 = from[1];
	to_next[0] = bi0;
	to_next[1] = bi1;
	from += 2;
	to_next += 2;
	n_left_to_next -= 2;
	n_left_from -= 2;

	b0 = vlib_get_buffer (vm, bi0);
	b1 = vlib_get_buffer (vm, bi1);

	/* udp leaves current_data pointing at the lisp header */
	if (is_v4)
	{
	vlib_buffer_advance (b0,
	-(word) (sizeof (udp_header_t) +
	sizeof (ip4_header_t)));
	vlib_buffer_advance (b1,
	-(word) (sizeof (udp_header_t) +
	sizeof (ip4_header_t)));

	iul4_0 = vlib_buffer_get_current (b0);
	iul4_1 = vlib_buffer_get_current (b1);

	/* pop (ip, udp, lisp-gpe) */
	vlib_buffer_advance (b0, sizeof (*iul4_0));
	vlib_buffer_advance (b1, sizeof (*iul4_1));

	lh0 = &iul4_0->lisp;
	lh1 = &iul4_1->lisp;
	}
	else
	{
	vlib_buffer_advance (b0,
	-(word) (sizeof (udp_header_t) +
	sizeof (ip6_header_t)));
	vlib_buffer_advance (b1,
	-(word) (sizeof (udp_header_t) +
	sizeof (ip6_header_t)));

	iul6_0 = vlib_buffer_get_current (b0);
	iul6_1 = vlib_buffer_get_current (b1);

	/* pop (ip, udp, lisp-gpe) */
	vlib_buffer_advance (b0, sizeof (*iul6_0));
	vlib_buffer_advance (b1, sizeof (*iul6_1));

	lh0 = &iul6_0->lisp;
	lh1 = &iul6_1->lisp;
	}

	/* determine next_index from lisp-gpe header */
	next0 = next_protocol_to_next_index (lh0,
	vlib_buffer_get_current (b0));
	next1 = next_protocol_to_next_index (lh1,
	vlib_buffer_get_current (b1));

	/* determine if tunnel is l2 or l3 */
	tl0 = next_index_to_iface (lgm, next0);
	tl1 = next_index_to_iface (lgm, next1);

	/* map iid/vni to lisp-gpe sw_if_index which is used by ipx_input to
	* decide the rx vrf and the input features to be applied */
	si0 = hash_get (tl0->sw_if_index_by_vni,
	clib_net_to_host_u32 (lh0->iid << 8));
	si1 = hash_get (tl1->sw_if_index_by_vni,
	clib_net_to_host_u32 (lh1->iid << 8));


	/* Required to make the l2 tag push / pop code work on l2 subifs */
	vnet_update_l2_len (b0);
	vnet_update_l2_len (b1);

	if (si0)
	{
	incr_decap_stats (lgm->vnet_main, cpu_index,
	vlib_buffer_length_in_chain (vm, b0), si0[0],
	&last_sw_if_index, &n_packets, &n_bytes);
	vnet_buffer (b0)->sw_if_index[VLIB_RX] = si0[0];
	error0 = 0;
	}
	else
	{
	next0 = LISP_GPE_INPUT_NEXT_DROP;
	error0 = LISP_GPE_ERROR_NO_TUNNEL;
	drops++;
	}

	if (si1)
	{
	incr_decap_stats (lgm->vnet_main, cpu_index,
	vlib_buffer_length_in_chain (vm, b1), si1[0],
	&last_sw_if_index, &n_packets, &n_bytes);
	vnet_buffer (b1)->sw_if_index[VLIB_RX] = si1[0];
	error1 = 0;
	}
	else
	{
	next1 = LISP_GPE_INPUT_NEXT_DROP;
	error1 = LISP_GPE_ERROR_NO_TUNNEL;
	drops++;
	}

	b0->error = error0 ? node->errors[error0] : 0;
	b1->error = error1 ? node->errors[error1] : 0;

	if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	{
	lisp_gpe_rx_trace_t *tr = vlib_add_trace (vm, node, b0,
	sizeof (*tr));
	tr->next_index = next0;
	tr->error = error0;
	tr->h = lh0[0];
	}

	if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED))
	{
	lisp_gpe_rx_trace_t *tr = vlib_add_trace (vm, node, b1,
	sizeof (*tr));
	tr->next_index = next1;
	tr->error = error1;
	tr->h = lh1[0];
	}

	vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next,
	n_left_to_next, bi0, bi1, next0,
	next1);
	}

	while (n_left_from > 0 && n_left_to_next > 0)
	{
	u32 bi0;
	vlib_buffer_t *b0;
	u32 next0;
	ip4_udp_lisp_gpe_header_t *iul4_0;
	ip6_udp_lisp_gpe_header_t *iul6_0;
	lisp_gpe_header_t *lh0;
	u32 error0;
	uword *si0;
	tunnel_lookup_t *tl0;

	bi0 = from[0];
	to_next[0] = bi0;
	from += 1;
	to_next += 1;
	n_left_from -= 1;
	n_left_to_next -= 1;

	b0 = vlib_get_buffer (vm, bi0);

	/* udp leaves current_data pointing at the lisp header
	* TODO: there's no difference in processing between v4 and v6
	* encapsulated packets so the code should be simplified if ip header
	* info is not going to be used for dp smrs/dpsec */
	if (is_v4)
	{
	vlib_buffer_advance (b0,
	-(word) (sizeof (udp_header_t) +
	sizeof (ip4_header_t)));

	iul4_0 = vlib_buffer_get_current (b0);

	/* pop (ip, udp, lisp-gpe) */
	vlib_buffer_advance (b0, sizeof (*iul4_0));

	lh0 = &iul4_0->lisp;
	}
	else
	{
	vlib_buffer_advance (b0,
	-(word) (sizeof (udp_header_t) +
	sizeof (ip6_header_t)));

	iul6_0 = vlib_buffer_get_current (b0);

	/* pop (ip, udp, lisp-gpe) */
	vlib_buffer_advance (b0, sizeof (*iul6_0));

	lh0 = &iul6_0->lisp;
	}

	/* TODO if security is to be implemented, something similar to RPF,
	* probably we'd like to check that the peer is allowed to send us
	* packets. For this, we should use the tunnel table OR check that
	* we have a mapping for the source eid and that the outer source of
	* the packet is one of its locators */

	/* determine next_index from lisp-gpe header */
	next0 = next_protocol_to_next_index (lh0,
	vlib_buffer_get_current (b0));

	/* determine if tunnel is l2 or l3 */
	tl0 = next_index_to_iface (lgm, next0);

	/* map iid/vni to lisp-gpe sw_if_index which is used by ipx_input to
	* decide the rx vrf and the input features to be applied.
	* NOTE: vni uses only the first 24 bits */
	si0 = hash_get (tl0->sw_if_index_by_vni,
	clib_net_to_host_u32 (lh0->iid << 8));

	/* Required to make the l2 tag push / pop code work on l2 subifs */
	vnet_update_l2_len (b0);

	if (si0)
	{
	incr_decap_stats (lgm->vnet_main, cpu_index,
	vlib_buffer_length_in_chain (vm, b0), si0[0],
	&last_sw_if_index, &n_packets, &n_bytes);
	vnet_buffer (b0)->sw_if_index[VLIB_RX] = si0[0];
	error0 = 0;
	}
	else
	{
	next0 = LISP_GPE_INPUT_NEXT_DROP;
	error0 = LISP_GPE_ERROR_NO_TUNNEL;
	drops++;
	}

	/* TODO error handling if security is implemented */
	b0->error = error0 ? node->errors[error0] : 0;

	if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	{
	lisp_gpe_rx_trace_t *tr = vlib_add_trace (vm, node, b0,
	sizeof (*tr));
	tr->next_index = next0;
	tr->error = error0;
	tr->h = lh0[0];
	}

	vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
	n_left_to_next, bi0, next0);
	}

	vlib_put_next_frame (vm, node, next_index, n_left_to_next);
	}

	/* flush iface stats */
	incr_decap_stats (lgm->vnet_main, cpu_index, 0, ~0, &last_sw_if_index,
	&n_packets, &n_bytes);
	vlib_node_increment_counter (vm, lisp_gpe_ip4_input_node.index,
	LISP_GPE_ERROR_NO_TUNNEL, drops);
	return from_frame->n_vectors;
	}

	static uword
	lisp_gpe_ip4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
	vlib_frame_t * from_frame)
	{
	return lisp_gpe_input_inline (vm, node, from_frame, 1);
	}

	static uword
	lisp_gpe_ip6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
	vlib_frame_t * from_frame)
	{
	return lisp_gpe_input_inline (vm, node, from_frame, 0);
	}

	static char *lisp_gpe_ip4_input_error_strings[] = {
	#define lisp_gpe_error(n,s) s,
	#include <vnet/lisp-gpe/lisp_gpe_error.def>
	#undef lisp_gpe_error
	};

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (lisp_gpe_ip4_input_node) = {
	.function = lisp_gpe_ip4_input,
	.name = "lisp-gpe-ip4-input",
	/* Takes a vector of packets. */
	.vector_size = sizeof (u32),
	.n_next_nodes = LISP_GPE_INPUT_N_NEXT,
	.next_nodes = {
	#define _(s,n) [LISP_GPE_INPUT_NEXT_##s] = n,
	foreach_lisp_gpe_ip_input_next
	#undef _
	},

	.n_errors = ARRAY_LEN (lisp_gpe_ip4_input_error_strings),
	.error_strings = lisp_gpe_ip4_input_error_strings,

	.format_buffer = format_lisp_gpe_header_with_length,
	.format_trace = format_lisp_gpe_rx_trace,
	// $$$$ .unformat_buffer = unformat_lisp_gpe_header,
	};
	/* INDENT-ON */

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (lisp_gpe_ip6_input_node) = {
	.function = lisp_gpe_ip6_input,
	.name = "lisp-gpe-ip6-input",
	/* Takes a vector of packets. */
	.vector_size = sizeof (u32),
	.n_next_nodes = LISP_GPE_INPUT_N_NEXT,
	.next_nodes = {
	#define _(s,n) [LISP_GPE_INPUT_NEXT_##s] = n,
	foreach_lisp_gpe_ip_input_next
	#undef _
	},

	.n_errors = ARRAY_LEN (lisp_gpe_ip4_input_error_strings),
	.error_strings = lisp_gpe_ip4_input_error_strings,

	.format_buffer = format_lisp_gpe_header_with_length,
	.format_trace = format_lisp_gpe_rx_trace,
	// $$$$ .unformat_buffer = unformat_lisp_gpe_header,
	};
	/* INDENT-ON */

	/**
	* Adds arc from lisp-gpe-input to nsh-input if nsh-input is available
	*/
	static void
	gpe_add_arc_from_input_to_nsh ()
	{
	lisp_gpe_main_t *lgm = vnet_lisp_gpe_get_main ();
	vlib_main_t *vm = lgm->vlib_main;
	vlib_node_t *nsh_input;

	/* Arc already exists */
	if (next_proto_to_next_index[LISP_GPE_NEXT_PROTO_NSH]
	!= LISP_GPE_INPUT_NEXT_DROP)
	return;

	/* Check if nsh-input is available */
	if ((nsh_input = vlib_get_node_by_name (vm, (u8 *) "nsh-input")))
	{
	u32 slot4, slot6;
	slot4 = vlib_node_add_next_with_slot (vm, lisp_gpe_ip4_input_node.index,
	nsh_input->index,
	LISP_GPE_NEXT_PROTO_NSH);
	slot6 = vlib_node_add_next_with_slot (vm, lisp_gpe_ip6_input_node.index,
	nsh_input->index,
	LISP_GPE_NEXT_PROTO_NSH);
	ASSERT (slot4 == slot6 && slot4 == LISP_GPE_INPUT_NEXT_NSH_INPUT);

	next_proto_to_next_index[LISP_GPE_NEXT_PROTO_NSH] = slot4;
	}
	}

	/** GPE decap init function. */
	clib_error_t *
	gpe_decap_init (vlib_main_t * vm)
	{
	clib_error_t *error = 0;

	if ((error = vlib_call_init_function (vm, lisp_gpe_init)))
	return error;

	gpe_add_arc_from_input_to_nsh ();
	return 0;
	}

	VLIB_INIT_FUNCTION (gpe_decap_init);

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/